I like tracking how many books my sims write and keeping an eye on the royalties, so I usually name them alphabetically within a genre with the titles all following the same (boring) pattern that I then try to make a bit silly. For children's books, one of my sims wrote a series 'Pat the ______' with as odd of animals as I could think of, and after Pat the Zooplankton he moved on to a children's series on plants (See the _____ Grow). My mystery writer had stories set in cities throughout the world, and my fantasy writer kept cycling through an alphabet of mythological creatures. If it's a biography, I name it after a sim in my game.
I don't bother naming paintings unless I hang it on the wall, and my sims paint far more than are kept. The ones I kept are named after things the paintings remind me of.
With songs, I give them names that I think suit the style of music and the sim who wrote it, but I don't follow patterns the way I do with books. The songs are written a lot less frequently.
